A forum for owners of Yamaha TTR250 trail and enduro bikes!

Dave · Veteran Member

Speedo inop

dan-reeves · Veteran Member

Hello

Recently riding back from dartmoor my speedo stopped working disbelief

It like judders just below 10mph but dosn't move at all.

What should i go for first the cable? or speedo drive?

Any ideas where to get any of these?

Any help would be great smile

Thanks Dan

Cubber · Super Guru

Check that the outer cable isn't damaged.
Undo the cable at the wheel end and see that the inner cable is in one piece.
If not then that's your answer.

If it seems in one piece then replace at the wheel and disconnect cable at speedo end.
Rotate the wheel and make sure that the inner is turning at the speedo head end.
If it does then the wheel drive and cable are OK and the speedo needs looking at.
If it doesn't then it's probably the drive that's the problam so it's wheel out and dismantle.

Maybe the washer and lack of thickness, wear, etc.

Luckily, it's not rocket science - unlike the sprocket drive sender magnetic rotor thingumyjig!

Martyn

TTRfan · Super Guru

My money is on the three tab washer in the axle drive being knackered!

Brian

dan-reeves · Veteran Member

Thanks for response, i will have a look tomorrow morning before work
Yeah at least it isn't the electrical one :/

Any ideas on where to get any parts?
I have tried Ebay, but found nothing...

Thanks
Dan

dan-reeves · Veteran Member

Hello

I have done the testing:

- The cable looks fine at both ends and turns manually
- When connected at the wheel end and disconnected at the speedo end and you turn the wheel, the cable doesn't turn at the speedo.

I guess this is a fault in the speedo drive?
Or the washers? confuse

Not knowing alot about either hmm , any susgestions?

Thanks smile

Dan

dan-reeves · Veteran Member

Thanks Dave i will look into it if this is the cause
Dan

TTRfan · Super Guru

dan-reeves wrote:
Hello

I have done the testing:

- The cable looks fine at both ends and turns manually
- When connected at the wheel end and disconnected at the speedo end and you turn the wheel, the cable doesn't turn at the speedo.

I guess this is a fault in the speedo drive?
Or the washers?
Not knowing alot about either , any susgestions?
Thanks
Dan

I think I am going to be proved right - it's the washer cry

Only way to check is to slip out the axle and you have immediate access to look inside the gear unit.

Brian

dan-reeves · Veteran Member

Ok i will give this a go tomorrow,

what am i looking for exactly? confuse Do you have any photos so i can compare?

How much are the washers?

Thanks alot for your help

Dan

TTRfan · Super Guru

Look for any damage to the worm gears but I expect you will find that the three tab washer is damaged. The only pic I can find is copied below. Look for damage to the washer where the green arrows are pointing.

I keep some stainless steel versions of the washer in stock which are much stronger than the originals but won't fix the problem if the worm gears are loose or damaged - or if there is grit or some other foreign body jamming up the works.

They are a "last resort" solution and can't be guaranteed. They are however worth a try as a new drive is about £140 retail.

Have a look and PM or email me if you would like to try a s/s washer.

Brian

Speedo drive.jpg

dan-reeves · Veteran Member

Brilliant, i will have a look tomorrow and let you no, possibly take a couple of pictures to see what you think.
Thanks for your help
Dan

dan-reeves · Veteran Member

Here are the photos i took today... sorry for the poor quality blankstare

-- Edited by dan-reeves on Tuesday 7th of February 2012 09:42:57 PM

dan-reeves · Veteran Member

Right i have removed front wheel and taken out speedo drive, the odd thing is every thing looks ok hmm

There is some play where the 3 tab washer interlocks with turning worm, but i cannot see why this would be a problem...

Also when i rode it just now the mileage doesn't increase as before i took it of the mileage still worked confuse

Hopefully someone has answers biggrin

Will post some pictures up in a moment

Thanks

Dan

TTRfan · Super Guru

Difficult to see from the pics but it doesn't take much damage for the 3 tab washer to slip on its mounting.

You said:

- The cable looks fine at both ends and turns manually
- When connected at the wheel end and disconnected at the speedo end and you turn the wheel, the cable doesn't turn at the speedo.

in which case the fault has got to be in the drive unit.

If you turn the worm gear that holds the washer does that turn the inner cable? Perhaps it's easier to stick a small screwdriver in where the cable fits and see what happens.

I am still thinking the fault is with the washer but willing to be corrected smile

dan-reeves · Veteran Member

When i turn the wheel (in your picture above) the other wheel spins so i don't think it could be the worm gears,
I suppose the only thing left to give a go would be the 3 tab washer...

I will pm you for a price.
Thanks
Dan

Dave · Veteran Member

Replacement Speedo Cable

Cubber · Super Guru

If the outer cable is not broken through to the inner then a temporary repair can be made by using a bit of see through plastic piping (petrol pipe) and splitting it along its length to cable tie to the speedo cable before clamping it back to the fork leg. wink

Other than that you need a new cable - the cable from a DT125LC Mk3 is a cheaper substitute.

Martyn

Dave · Veteran Member

Thanks Martyn,

It has gone through to the inner so I've just found one via Yambits for £6.50!

Mr_Blonde · Member

RE: Speedo accuracy

TTRfan · Super Guru

If you go back to standard gearing then the speedo should be more accurate.

For anyone running non-standard gearing, digital speedos can be corrected to read accurately using the Speedo DRD - see http://www.ttr250.com/TTR_extras/index#SpeedoDRD

Brian

Mr_Blonde · Member

Thanks Brian,I will look into the Speedo DRD-it looks like the way to go.
Don

BaronGreenback · Veteran Member

Speedo drive

MuzzaNZ · Veteran Member

Improving waterproofing for the digital speedo sender?

TTRfan · Super Guru

Hi there and welcome to the forum!

It is true that it is moisture that usually kills the sender units but this usually takes a decade or so to happen.

The guy that does our sender unit repairs says the moisture makes its way down the wires to the Hall sensor so its the connector you want to look at waterproofing.

Brian

PS Nice pic by the way - we like pics on here biggrin biggrin

TTRfan · Super Guru

RE: Speedo drive

BaronGreenback · Veteran Member

Thanks, that's good to know.

barra8 · Guru

RE: Improving waterproofing for the digital speedo sender?

MuzzaNZ · Veteran Member

Thanks guys - I think both suggestions are good. Some RTV around the top of the sensor (where the wire goes in and the connector above) and some grease in behind the magnet and against the seal is the way to go if sticking with stock. Maybe also some RTV around the front seal too for good measure. My bike is low in kms for its age, but solely used off road so does receive the accellerated wear test! The rivers in New Zealand are very braided so there is an aweful lot of multiple crossings....

tiddler · Veteran Member

Remember to put some silicone grease in the connector block where the sensor wiring joins the main loom. As Brian says, water will find its way down inside the wiring between the copper and the plastic sheath.

Giles

noeyedear · Senior Member

digital speedo conversion

TTRfan · Super Guru

I bought a white TTR with a Vapor speedo and it worked just fine. However, it is nowhere near as nice as having the original speedo working!

The stainless steel tab washers are usually a reliable fix if the speedo cable is lubed and spins freely and there is no grit or dirt in the drive unit's worm gears and the gears aren't damaged. Did the inside of the tab washer round out or jump the drive? Happy to post you a replacement to try if you want.

New speedo gear units for the blue TTRs aren't cheap but can work out to cost not a great deal more than a new Vapor and certainly easier to fit wink

Cheers

Brian

noeyedear · Senior Member

Will strip it down again tomorrow evening, & have another look. also need.to fit the new silencer, thanks Brian &Andy. and I do like original speedo so would prefer to keep again it, but if the drive unit bit is ###### will Adrian have to see £ for £.

TTRfan · Super Guru

noeyedear wrote:
Will strip it down again tomorrow evening, & have another look. also need.to fit the new silencer, thanks Brian &Andy. and I do like original speedo so would prefer to keep again it, but if the drive unit bit is ###### will Adrian have to see £ for £.

Have a look at what's gone wrong in the drive first Adrian but, if you think you need a new gear unit, I am sure I can cut you a good deal bearing in mind all those other goodies you have your eyes on such as Symtec heated grips, shorty header, frame guards etc wink

Brian

MuzzaNZ · Veteran Member

RE: Improving waterproofing for the digital speedo sender?

noeyedear · Senior Member

RE: digital speedo conversion

TTRfan · Super Guru

noeyedear wrote:
Ok have it all apart again, and all turns freely. speedo cable all greased up and turns freely. Have noticed the three tabs inside the hub have small amounts missing and a bit of a groove. any ideas on maybe filling with chemical metal ??

Any chance of putting up a good quality pic showing the hub damage please?

Brian

BM Steve · Guru

Improving waterproofing for the digital speedo sender?

noeyedear · Senior Member

RE: digital speedo conversion

TDVT · Senior Member

noeyedear wrote:
Hi all. the speedo on my blue ttr stopped working the other week. so I bought the new stainless tab washer, which worked for a bit, then packed up again. So now I am looking at a vaportec digital speedo or simmilar. So have any of you had any experiance with these or fitted one to your ttr ? cant be doing without speedo, will end up getting myself into trouble , thanks Adrian

I have a Trail Tech Vector on my TTR, quite happy with it.

Easy to install as well, see this thread: http://ttr250.activeboard.com/t50132515/making-my-us-ttr-street-legal/

-- Edited by TDVT on Wednesday 19th of December 2012 08:33:28 PM

noeyedear · Senior Member

you can see the chip in the tab. all 3n are the same. any ideas ?

Adrian

barra8 · Guru

You can have it alloy welded or try to use a metal repair such as Kneed it works good but there are also more metal repair options available.

.................................

Jarrah.

noeyedear · Senior Member

Have gone with squaring the tabs off with a file. only a little shorter than original. have found nothing wrong with drive gears, the only thing
I can see.is a very worn bottom washer, that must of let the gear lift and jam.

TTRfan · Super Guru

Is there a way to test the digital sender?

boredus · Veteran Member

Had a run up the drive this weekend and noticed the speedo didnt pick up.

Read a few posts and it appears the sender could be at fault, is there a way to test this one at home before sending off for a refurb?

boredus · Veteran Member

hmm, Youtube is my friend! off to try something

TT-R250M · Super Guru

Speedo Drive

Robert Lithgow · Newbie

I have dismantled the speedo drive (blue/mechanical model) and need a new toothed steel drive.

I see on the net that is a a common problem and that Yamaha, in NZ and elsewhere only sell the complete unit at $180 + equiv.

You have a stainless steel replacement made and available.

I am just commenting at the toothed disc appears to be low grade steel and intended to be sacrificial to protect the brass worm drive ? The first failure occurred by deforming the teeth and was fixed by bending them back to mesh with the cast cog.

This time the worm drive seized with grit and the speedo drive slightly deformed; then has worn off the flat edges that mate with the flat sides of the central spindle.

I am going to have them rebuilt with a strip of weld until I can establish that is the only problem andget a new drive - probably from you.

I simply ask two questions:

1. My worm drive only goes one way. Is it supposed to be like that is was that the cause of the problem (ie I damaged the flat faces by rolling backwards when the worm gear was seized ?)

2. Is it in fact a good idea to have a stiffer stainless steel drive disc because I am thinking that next time it will continue turning and destroy the more expensive clogged up componets eg the brass worm drive ?

any ideas gratefullly received.

Mike Wright · Veteran Member

Speedo Q&A mega thread

Mike Wright · Veteran Member

RE: Digital Speedo Sensor

mossproof · Super Guru

Hi Mike,
No, the magnet should be tight between the 2 chrome washers. If it spins freely it won't give you an accurate reading. If the magnet's complete you should be able to glue it, otherwise, Brian at Totallyttrs can supply exchange units.
Simon.